GTK: Use correct button mask on reload button.
GTK: Use correct button mask on reload button.

BUG=41530
TEST=Install GoodSmile theme. The right corners of the reload button shouldn't be rounded.

Review URL: http://codereview.chromium.org/1625014

git-svn-id: http://src.chromium.org/svn/trunk/src@44555 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: be1c93ef5b368e33f8a3997372250f1c8695d394
meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser